Comment 51 for bug 320057

Digging through MsgComposeCommands.js, I found that the filter string can be customized by setting ldap_2.servers.<NAME>.autoComplete.filterTemplate.
I set it to (|(cn=*%v1*)(mail=*%v1*)(sn=*%v1*)),
now the query is equivalent to the one executed by the address book - but the widget still hangs.
So the double asterisk is not to blame for this behavior.